Multiple resistor unit



Nov. 5, 1957 R. A. JARBOE 2,812,471

I MULTIPLE RESISTOR UNIT Filed OG- C. 14, 1955 2 Sheets-Sheet l INVENTOR. P4700 7 6'. e/a/aa I ATTORN United States Patent U MULTIPLE RESISTOR UNIT Rupert A. Jarboe, Kansas City, Mo., assignor to Electra Manufacturing Company, Kansas City, Mo., a corpo ration of Missouri Application October 14, 1955, Serial No. 540,566

2 Claims. (Cl. 315--8.5)

This invention relates to the fields of multiple resistance electrical components and electronic tubes. More particularly, the invention is concerned with the provision of an improved multiple resistance unit ideally adapted for incorporation within vacuum tubes so that a part of the electrical circuitry normally associated with such tubes may be embodied in the tubes themselves with resultant improvement in the operating characteristics of the tubes and the circuitry in which they are employed.

Prior to this invention, it has been necessary for resistance units connected with the internal elements of an electronic tube to be either disposed externally of the tube, which results in the necessity for relatively long connecting conductors or leads between the tube elements and the resistance units detrimental to the operation of the circuitry in which the tube and resistance units are employed by virtue of stray capacitance or the like, or to provide individual resistors within the envelope of the electronic tube, which necessitates the miniaturization of the resistors to a point affecting their accuracy or stability.

Accordingly, it is the primary object of this invention to provide a novel and improved multiple resistance unit adapted for incorporation within an electronic tube as a component or element thereof which will overcome all of the above mentioned and other disadvantages inherent in previously known means for attempting to accomplish the shortening and minimization of the number of leads that is so desirable, if not necessary, in a number of types of electrical circuits. It will be understood that the multiple resistance units of this invention are also adapted for use in applications other than in electron tubes, and such uses thereof are within the contemplation of the invention.

It is another important object of this invention to provide an improved multiple resistance unit principally comprised of a disc of ceramic material having a peripheral edge on which a layer of conductive material has been deposited, a number of perforations in which a layer of conductive material has been deposited and which are adapted to receive in electrically contacting relationship a conductor or conductive part of a tube element, and a plurality of strip-like layers of resistance material deposited upon the faces of the disc and extending in predetermined arrangement between said perforations and said peripherally disposed conductive layer.

Although the multiple resistance unit of this invention may be used in various types of electron tubes, it is particularly adaptable for use in a beam switching type electron tube, and it is an important object of this invention to provide a multiple resistance unit especially suited for inclusion in a beam switching tube as an integral part thereof.

Other important objects of this invention, including many significant details of construction and the manner in which the invention minimizes manufacturing costs, improves tube and circuit performance and decreases maintenance requirements, will be made clear or become apparent as the following description of the invention progresses.

In the accompanying drawing:

Figure 1 is a fragmentary perspective View of a portion of an electron tube having one of the multiple resistance units contemplated by this invention incorporated therein, parts being broken away for clarity of illustration;

Fig. 2 is a plan view of one face of an embodiment of multiple resistance unit made in accordance with the invention;

Fig. 3 is a plan view of the opposite face of the unit illustrated in Fig. 2;

Fig. 4 is an enlarged, fragmentary, cross-sectional view taken on line IV-IV of Fig. 2;

Fig. 5 is an elevational view of an electron tube showing one of the multiple resistance units of this invention incorporated therein, only such detail of the tube as is believed necessary to illustrate the relative disposition of the resistance unit within the tube envelope being shown;

Fig. 6 is a diagrammatic representation of a typical beam switching tube, together with certain portions of one type of circuitry conventionally employed therewith; and

Fig. 7 is a schematic representation of the electrical aspects of the tube and circuitry illustrated in Fig. 6.

For purposes of illustration, the invention may, and will, be explained with particular reference to its adaptability for application as a component part of a beam switching type electron tube. Those skilled in the art will readily understand how the invention may be employed in connection with tubes of other types and in other differing applications.

Referring now particularly to Figs. 1 and 5, the numeral 10 generally designates a beam switching type electron tube having an evacuated glass envelope 12 containing a multiple resistance unit generally designated 14 of the type contemplated by this invention and a number of internal electrodes or tube elements generally designated 16 having portions generally designated 18 in electrical contact with portions of the unit 14 housed therewithin. Tube 10 is also provided with a number of connecting pins generally designated 20, which are respectively coupled electrically with various of tube elements 16 by leads generally designated 22.

Referring now more particularly to Figs. 6 and 7, it will be seen that a typical type of pin positioned beam switching tube and the circuitry normally associated therewith include a tube cathode 24 for emitting an electron beam 26, and ten positional sets of tube elements 16 each corresponding to a digit from zero to nine and including a beam forming and locking spade 23, a switching grid 30 and a target output plate 32. The spade, grid and plate associated with the zero position are designated respectively 28, 3t) and 32 for purposes of identification, the positions or sets of tube element 16 corresponding to successively increasing digits being disposed in a clockwise direction from the zero position set in Fig. 6 and from right to left in Fig. 7. The grid 30' and the grids 30 of alternate sets corresponding with each even numbered position are interconnected by conductive means 34 (illustrated only in Fig. 7), while the remaining grids 30 corresponding to the odd digital positions are inter connected by conductive means 36 (shown only in Fig. 7). In ordinary tube manufacturing practice, the interconnections 34 and 36 are effected within the tube by split, generally annular bands (not shown) contacting an extremity of the appropriate grids Similarly, all of the plates 32, except plate 32, are electrically interconnected by conductive means 38 in the nature of a band or the like (not shown) within the tube 10, the plate 32 Patented Nov. 5, 1957' being provided with an individual lead 40. Cathode 24 and conductive means 38, 34,- 36 and 40 will normally be coupled respectively with pins 20 more particularly identified by the numerals 42, 44, 46, 48 and 50. It will now be observed, however, that the circuitry illustrated, which is typical, requires that the spade 2 8' be coupled with a pin 52 through an electrical resistance 54, while the remaining spades 28 must be connected in common to a pin 56 through individual series resistances 58, 60, 62, 64, 66, 68, 70, 72 and 74'and' conductive means 76.

In the o eration of the beam switching tube 16 and its associated circuitry just referred to, it is necessary for optimum performance and reliability that stray capacitance betweenthe spades '28 and, more particularly,- any leads from such spades 28 to the respective resistances 54, 58, 60, et seq., be minimized. This operating requirement is so stringent that the capacitance existing between leads running from the spades 28 to resistors disposed externally of the tube is virtually prohibitive, and even that capacitance existing between miniaturized, conventional, cylindrical, depositedtor wire wound resistances disposed within the tube envelope 12 ismarkedly deleterious on the operation of the circuitry,

Such problem is solved by the unit 14 of this invention which will be seen from Figs. 2-4 inclusive to be comprised of a thin, circular, ceramic disc or water 80 having an annular marginal edge 82 and a pair of opposed faces 84 and 86, together with conductive and resistive structure hereinafter to be described.

An annular layer 88 of conductive material such as silver, is deposited upon the edge 82 of disc 80 to provide a common line or terminal corresponding to the conductive means 76 illustrated in Figs. 6 and 7.

The disc 80 is provided with a pair of openings 90 and 92' used to receive structures 94 and 96' (see Fig. 1')

'upon which the disc 80 is mounted within the tube 10.

A hole 28 is provided in disc 80 for receiving a condu'c-' tive element 100 (see Fig, 1) withintube 10, which is used for coupling the conductive band 88 (corresponding to the conductive means 76 of Figs. 6 and 7) to the pin 56 of tube 10, such hole 98 being provided with an internally deposited layer 102 of conductive material such as silver for eliecting electrical contact with the conductor 100. It may also be noted that the conductive layer 102 extends radially as at 104 into electrical contact with the conductive layer 88. 7

Disc 80 is also provided with a central opening 106 for accommodating the upper extremity of cathode 24 and with a hole 108 adjacent opening 106 for establishing electrical contact, by means of an internal conductive coating 110 with a conductor element 112 (see Fig. 1) provided within tube 10 and leadingv to the pin 52.

Arranged outwardly from opening 108' and inwardly from openings 90, 92 and 98 are an annular row often holes respectively designated 200, 201, 202, 203, 204,

I identified in Figs. 2 and 3 by the same numerals appearing in Figs. 6 and 7. p p f It will now be apparent" that the strip-like deposited resistances 54 and 58, 60, 62 et seq. may be conveniently divided between the faces 84 and 86 of disc 80 and thereon arranged in manner providing for the lengths necessary to effect the proper electrical resistancefwhile still maintaining configurations and relative positioning which will minimize stray capacitance therebetween. As is well known to those skilled in the art, such capacitanceis considerably minimized by virtue alone of the thin crosssectional configuration of the strip-like resistances their substantially coplanar relationship.

It Will now be further apparent that the structure contemplate'd and provided by this invention is ideally suited for solving all of the problems and attaining all of the objectives hereinbefore referred to. Manifestly, however, certain min'or' modifications and changes could be made from the exact details disclosed for purposes of illustration without materially departing from the true spirit and intentionof'the' invention. Accordingly, it is'to' be under stood that the invention shall be deemed limited only by the scope ofthe appended claims.

Having thus described the invention What is claimed as new and desired to be secured by Letters Patient is:

f. In an electron tube, an evacuated envelope; a number of tube elements within the envelope; a disc of insulating material within theenvelope, said disc having a number of holes therethreu n, portion of aplurality' of said elements extending into corresponding holes for physical support by the disc; a conductive structure secured to the disc Within each of said holes in electrically contacting relationship with a corresponding tube element portion; a band of conductive material deposited upon the periph cry of the disc; and a plurality of strips of resistance material deposited upon the disc and respectively extending from different ones of said structures to said band.

2. In an electron tube, an evacuated envelope; a number of tube elements within the envelope; a disc of insulating material Within the envelope, saiddisc having a number of holes therethrough, a portion of a plurality of saidelements extending into corresponding holes for physical support by the disc; a conductive structure secured to the disc within each of said holes in electrically contacting relationship with a corresponding tube element portion; aband of conductive material deposited upon the periphcry of the disc; and a plurality of strips of resistance material deposited upon the disc and respectively extending from different ones of said structures to said band and between diflerent pairs of said structures.

References Cited in the tile of this patent UNITED STATES PATENTS 2,616,994 Luhn 2 Nov. 4, 1 952 2,620,454 Skellct, -2 2 22. 1366.2, 1952 2,629,166 Marstenet al Feb. 24, 1953 2,721,955 Fan et al. Oct. 25, I955 

